This chapter on shotcrete has not appeared in prior editions of ASTM STP 169 and makes its debut in this version, ASTM STP 169C. Shotcrete has been a viable and important process in concrete construction for almost 80 years, yet it has only been universally accepted worldwide in the past 30 years or so. Its versatility and applicability to a large variety of singular uses provides an economical alternative and complement to conventional concrete construction. The upsurge in its use has led to greater interest in shotcrete, its capabilities, liabilities, and the nature of its distinct characteristics. It is said that the design and application of shotcrete is more art than science and, consequently, the process is less susceptible to standardization than concrete. Nevertheless, it has become apparent in recent years that there is a need to improve and assure the quality of shotcrete installations by the establishment of appropriate standards.